Theoretical Determination of Net Radiation Force and Torque for a Spherical Particle Illuminated by a Focused Laser Beam.

摘要

Series expressions for the net radiation force and torque for a spherical particle illuminated by an arbitrarily defined monochromatic beam are derived utilizing the spherical-particle/arbitrary-beam interaction theory developed in an earlier paper. Calculations of net force and torque are presented for a 5-micrometer diam water droplet in air optically levitated by a tightly focused (2 micrometer beam waist diameter) TEM(00)-mode argon-ion (lambda = 0.5145 micrometer) laser beam for on and off propagation axis, and on and off structural resonance conditions. Several features of these theoretical results are related to corresponding experimental observations. Reprints. (jhd)